Fixing JS errors caused by bug 172545.

r=neil, sr=sspitzer, a=asa

xpfe/components/bookmarks/resources/bookmarks.xml

@@ -938,6 +938,10 @@
         {
         },
 
+        getImageSource: function BMOLBuilderObserver_getImageSource(aItemIndex, aColumnID)
+        {
+        },
+        
         onSetCellText: function BMOLBuilderObserver_onSetCellText(aItemIndex, aColumnID, aValue)
         {
         },